Adding the B vitamin folic acid to flour has been the subject of five years of debate in Britain some have heralded this as a way to lower the number of births affected by neural tube defects (NTDs), which affects around 900 pregnancies a year. However, two studies carried out last year raised questions on whether a greater intake of folic acid could encourage cancer in some areas of the population. The Food Standards Agency (FSA) was supposed to decide on whether to introduce mandatory folic acid fortification of bread or flour some time this year, following advice from the Scientific Advisory Group on Nutrition (SACN). However, it will now delay its decision until the middle of 2009, when it will have reviewed a further two studies that will be completed at the end of this year. Investigation into folic acid Last May, the FSA board decided to recommend that health ministers introduce mandatory fortification of bread of flour with folic acid. It estimated such action alone could reduce NTD births by about a third - from 1,100 to 350-400. However, it subsequently called on food manufacturers to consider reducing folic acid levels in some foods to ward against overexposure at the same time two reports were released on links between folic acid and cancer. Cole et al (Journal of the American Medical Association) conducted a randomised trial that investigated the potential of folic acid in the prevention of new growths forming on the colon in a group of patients who already had some removed, at a time when mandatory fortification was introduced in the USA. There was no evidence to show that folic acid supplementation was successful. Furthermore, there was a significantly greater incidence of advance lesions in the folic acid group compared to the placebo group. A paper by Mason looks at a temporal association between folic acid fortification and an increase in colorectal cancer in the USA and Canada. Mandatory fortification was in place in the US by the beginning of 1998 and in Canada the following year. The FSA is set to wait for results of a new US study that will investigate the effect of folic acid on the risk of bowel cancer. Another study that will form part of the FSA's review is an assessment of pooled data from trials investigating the effect of folic acids on cardiovascular disease (CVD) that will also collect data on cancer risk. 'Concerns are unfounded' Liam Donaldson, a member of the SACN, said that while the trial by Cole raised concerns, the increased risk of colectoral cancer "appears to be associated with doses in excess of the upper safe level of 1mg per day of folic acid". Donaldson also said the trend data in the Mason study "might be explained either by increased screening or by increased intakes of folic acid as a result of fortification". There has been backlash within the industry over the FSA's hesitancy in requiring manufacturers to use flour fortified with folic acid. Last month, Folic Acid Action (FAA) said that the FSA's position "lacks clarity" and its concerns were "unfounded". It said no risks had actually been proven over increased consumption of folic acid. At the same time, the organisation insisted the vitamin helped reduce dementia in the elderly and CVD, as well as helping against NTDs. It is estimated that around 13.3m people in the UK currently consume too little folate, natural dietary sources of which include grains, lentils, chick peas and green leafy vegetables. No other European country has yet introduced the measure, but Ireland is at an advanced stage in the process.